The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in HEVs use one or more propulsion systems to provide motive power. The propulsion systems include an electrical system that receives power from a battery pack. A battery pack typically includes one or more battery modules that each includes a plurality of high-voltage cells (or batteries) such as lithium ion cells. A battery management system controls current flow between the battery pack and the electrical system.
The battery management system includes a battery disconnect unit (BDU) and a battery control unit (BCU). The BDU is the primary interface between the battery pack and the electrical system. The BDU includes electromechanical switches that open or close high current paths between the battery pack and the electrical system. The BDU provides feedback to the BCU such as voltage and current measurements. The BCU controls the switches in the BDU using low current paths based on the feedback received from the BDU.